Dyer: It’s abrupt climate change, stupid

There is nothing temperate about extreme heat waves, blizzards and flooding

This is not how it was supposed to happen. The standard climate change predictions said that people in the tropics and the subtropics would be badly hurt by global warming long before the people living in the temperate zones, farther away from the equator, were feeling much pain at all.

That was unfair, because it was the people of the rich countries in the temperate zone — North America, Europe and Japan, mainly — who industrialized early and started burning large amounts of fossil fuel as long as two centuries ago. That's how they got rich. Their emissions of carbon dioxide over the years account for 80 per cent of the greenhouse gases of human origin that are now in the atmosphere, causing the warming, yet they get hurt least and last.

Well, what did you expect? The gods of climate are almost certainly sky gods, and sky gods are never fair. But they have always liked jokes, especially cruel ones, and they have come up with a great one this time. The people of the temperate zones are going to get hurt early after all, but not by gradual warming. Their weather is just going to get more and more extreme: heat waves, blizzards and flooding on an unprecedented scale.

"In 2012 we had the second wettest winter on record and this winter is a one-in-250-years event," British Opposition Leader Ed Miliband told The Observer newspaper last Friday. "If you keep throwing the dice and you keep getting sixes then the dice are loaded. Something is going on."

In the United States and Canada, it’s huge blizzards, ice storms and record low temperatures that last much longer and reach much further south than normal.

The "something" is abrupt climate change. In Britain, it's an unprecedented series of great storms blowing in off the North Atlantic, dropping enormous amounts of rain and causing disastrous floods. In the United States and Canada, it's huge blizzards, ice storms and record low temperatures that last much longer and reach much further south than normal. Welcome to the "temperate" zone of the Northern Hemisphere.

There have been extremes in the "temperate" parts of the Southern Hemisphere, too. Australia has just had the hottest year ever, with record-breaking heat waves and severe bush fires. Argentina had one of its worst-ever heat waves in December, and parts of Brazil had record rainfall, floods and landslides. But that is probably just the result of gradual, relentless warming. The abrupt changes seem to be mainly in the Northern Hemisphere.

Geography may explain the differences. There isn't all that much land in the southern temperate zone, and the vast expanses of ocean that surround it moderate the land temperatures. Moreover, the polar jet stream in the Southern Hemisphere simply encircles the Antarctic continent, and does not operate over land — whereas the northern polar jet stream flows right across North America and Europe. And it's the jet stream that matters.

The extreme weather trend in North America and Europe is less than five years old, so the science that might explain exactly what is happening is still quite tentative. The first hypothesis that sounded plausible, published in 2012 in Geophysical Letters, blamed a slowing of the Northern Hemisphere's polar jet stream.

The paper, entitled Evidence Linking Arctic Amplification to Extreme Weather in Mid-Latitudes, was written by Jennifer Francis of Rutgers University and Stephen Vavrus of the University of Wisconsin-Madison. The authors' methodology has been challenged by other climate scientists, but I think in the end Francis and Vavrus will turn out to be largely right. That is not good news.

They start with the fact that the Arctic has been warming faster than anywhere else on Earth, so the difference in temperature between the Arctic air mass and the air over the temperate zone has been shrinking. Since that difference in temperature is what drives the jet stream that flows along the boundary between the two air masses, a lower difference means a slower jet stream.

Now, a fast jet stream travels in a pretty straight line around the planet from west to east, just like a mountain stream goes pretty straight downhill. A slower jet stream, however, meanders like a river crossing a flood plain — and the big loops it makes extend much further south and north than when it was moving fast.

In a big southerly loop, you will have Arctic air much further south than usual, while there will be relatively warm air from the temperate air mass in a northerly loop that extends up into the Arctic. Moreover, the slower-moving jet stream tends to get "stuck," so that a given kind of weather — snow or rain or heat — will stay longer over the same area.

Hence the "polar-vortex" winter in North America this year, the record snowfalls in Japan in 2012 and again this winter, the lethal heat waves in the eastern U.S. in 2012 — and the floods in Britain this winter.

"They've been pummelled by storm after storm this winter (in Britain)," said Jennifer Francis at the American Association for the Advancement of Science conference in Chicago last week. "It's been amazing what's going on, and it's because the pattern this winter has been stuck in one place ever since early December." There's no particular reason to think that it will move on soon, either.

Gwynne Dyer is an independent journalist whose articles are published in 45 countries.

Gwynne Dyer is a London-based independent journalist whose articles are published in 45 countries.

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(8) Comments

By veryoldguy|FEBRUARY 21, 2014 10:28 AM

We are all entitled to our opinions but scientists deal with facts. I'll believe scientists over Sun Media, everytime.

What do you call a 31 year old consensus of nothing beyond; "could be" a cataclysmic CO2 crisis?
You call it a 31 year old consensus of nothing beyond; "could be" a cataclysmic CO2 crisis.
How many remaining climate blame believers does it take to change a light bulb?
None, because they choose to remain in the dark about science’s 31 year old consensus of nothing beyond; “could be”.
Yes these humanity haters lie to their own kids telling them that science "believes" as much as they do that the end is near. Who is the neocon?

It's hard to show Global Warming this winter. My biggest supprise when transcribing Peter Van Wagner's diary from 1850 to 1906 was how many times they had rain at Christmas and New Years. My thoughts were always that winters 100 years ago were so much colder and lasted from Nov to April. But it doesn't seem to be alot different over the past 175 years.
You think the weather is crazy NOWADAYS. The following is from Peter Van Wagner's diary 1896
April 15th "about 80 DEGREES"
April 17th "Temperatures in the city in the shade at noon 94 DEGREES.
April 23rd "rather cold, a WHITE FROST"

continued from below...
We have an impact, of course, but the remedies devised by the new saints of the environment make scientific solutions and real pollution abatement impossible – in their place the politicians who can’t gain power in any other way, have a platform for the social engineering based on power and politics, with little regard for the environment, locally or globally.

continued from below...Ironically, these captains of the new religion and the journalist along for the ride are themselves the worst offenders, living with the biggest carbon footprints while they tell the working people that they must pay more and follow the new religion. It was the same in Communist Russia where everyone was brought down so they would not complain about the jackboots of the commy dictatorship. Climate has always been changing, with or without man. continued above...